Throttle control mechanism



April 6, 1935. c. CUMMINS 1,997,575

'I'HROT ILE CONTROL MECHANISM Filed March 9, 1934 I? z/e'7r 071' CZeaazel 02172271202 yw W,

Patented Apr. 16, 1935 1,997,575 THROTTLE CONTROL MECHANISM Clessie L. Cummins, Columbus, Ind., assignor to Oil Engine Development Company,

Columbus,

Ind., a corporation of Indiana Application March 9, 1934, Serial No. 714,7 96

10 Claims. (Cl. 105-48) My invention relates to a throttle control mechanism for internal combustion engines, particularly oil engines, and is concerned primarily with a mechanism for preventing the movement of the throttle to full open position until the vehicle propelled thereby has attained a predetermined speed.

It is characteristic of oil engines that practipally their full power is available when starting under load. This condition is advantageous where the principal operative requirement is rapid acceleration, but is a positive detriment unless properly controlled where, for example, the engine furnishes the motive power for a shifting locomotive in a railroad yard. Because of the high starting torque of the engine, the tendency of the shifting crew is to couple as many cars as the locomotive is capable of moving, with the result that the train cannot be accelerated and therefore is moved at a slower rate of speed than is demanded by eflicient shifting service.

It is therefore the principal object of my invention to devise a mechanism which prevents the utilization of the full power of the engine when starting under load by interposing a stop in the path of movement of the throttle lever short of the latter's full load position, and which is automatically shifted to a clear position when the vehicle attains a predetermined speed.

A further-object is to devise a mechanism of the character indicated in which the position of the stop is dependent upon, and automatically controlled by, the speed-of the vehicle, and in which the relation between the stop and throttle lever is such that the latter may be moved from full-load to no-load position, notwithstanding that the stop may then be occupying an interrupting position due to a decrease in the vehicle speed.

A further object is to provide a speed governed, throttle control mechanism which may be conveniently connected to an axle of the locomotive, for example, and in which the specific mechanism may take the form of mechanical, fluid or electrically operable devices.

These and further objects of my invention will be set forth in the following specification, reference being had to the accompanying drawing, and the novel means by which said objects are efiectuated will be definitely pointed out in the claims.

In the drawing:

Figure 1 is a diagrammatic view, partly in section, showing a mechanically controlled mechanism for limiting the. movement of the throttle lever toward full-load position, the lever being shown in the maximum position which it may assume until the locomotive attains a predetermined speed. 5

Figs. 2 and 3 are diagrammatic views similar to Fig. 1, showing, respectively, hydraulic and electrical devices for controlling the throttle lever.

Referring to Fig. 1, the numeral III designates 10 a wheel of a locomotive, for example, which is mounted on the usual axle H that may have afilxed thereto a pulley l2. A belt 13 operates over the pulley l2 and also over a second pulley I4 secured to a shaft l5 which is joumaled in 15 a suitable bearing IS. The shaft l5 extends to the left of the bearing and has afilxed thereto a pair of arms l1 upon which are pivotally I mounted a pair of fly-ball levers I 8, the inner arms is of which are in constant bearing en- 20 gagement with one end of a sleeve 20 that is journaled upon an extension 2| of the shaft IS. The left end of the sleeve is formed with an annular channel 22 and a coil spring 23, which encircles theleft extremity of the extension 2!, 25 bears against the left end of the sleeve 28 and also against a head 24 provided on the extension 2|. The tendency of the spring 23 to extend in length causes the sleeve 20 to bear constantly against the lever arms I9.

A lever 25 is pivoted at 26 upon a convenient supporting structure and the upper end of the lever is formed as a nose for constant retention in the annular channel 22. The lower end of this lever is connected to one end of a cable 21 35 whose opposite end is fastened to a stop 28 that is slidably mounted in a casing 29. A coil spring 30 encircles the cable 21 within the casing and tends to normally project the stop 28 without the casing for engagement with the lower end 40' of a throttle lever 3| that is pivoted as at 32. The no-load position of the throttle lever is indicated bythe dotted line 33 and the full-load position thereof by the dotted line 34, the lever being shown in the maximum position to which it can be moved owing to its engagement with the stop 28. Preferably, the lower end of the lever 3| and the upper end of the stop 28 are provided with inclined cam surfaces 35 and 38, respectively, so that the throttle lever can be returned to the no-load position from any position between the intermediate position, as shown, and the full-load position, notwithstanding that the stop 28 may be occupying the position shown in Fig. 1. During this return movement, it will be obvious that the cam surfaces will cause the stop 2! to be moved downwardly in the casing 29 until the lever II has cleared the upper end of the stop.

In the relation of the parts as shown, the interrupting position of the stop 2! is indicated as permitting a movement of the throttle lever through approximately two-thirds of its range from no-load position, although this relation may be varied as desired. In the operation of this mechanism, the ily-balls It will be adjusted so that, at some predetermined speed of the locomotive, they will move outwardly sumcient to cause a sliding of the sleeve 2| toward the left and consequently a retraction of the stop ll within the casing. This releasing movement of the fly-balls may be set for as low as a speed of five miles per hour, or at any speed which the operating requirements demand. When the speed of the locomotive tails below the indicated critical speed, the stop will be returned to interrupting position. I

In the hydraulic arrangement shown in Fig. 2, the numeral 31 designates a belt which operates over a pulley ll. corresponding to the belt I: and pulley i4, respectively, in Fig. 1, it being assumed that the belt 81 is driven from the locomotive axle as above described.

The pulley 88 is drivably connected to a shaft 39 of a hydraulic pump 4| which may be of the gear type, and this pump is connected by a fluid line I to a source of liquid 42. The delivery side of the pump is connected by a line 43 to a cylinder 44 within which is reciprocably mounted a piston ll having a piston rod 48 which proiects without the casing and operates as a stop for the throttle lever 41. A coil spring 48 is disposed in the casing 44 below the piston 45 and normally tends to maintain the stop 48 in the throttle lever interrupting position shown in Fig. 2. A by-pass line I connects the lines Ii and 43 around the pump 40 and in this line is located a valve 50 which may be adJusted to provide for any suitable relieving flow such that, when the locomotive attains a predetermined speed, as before described, suiiicient pressure will be created above the piston 45 to effect a withdrawal of the stop It. When the speed of the locomotive falls below this predetermined speed, the spring I again returns the stop 4' to interrupting position and, as in the case of the mechanism shown in Fig. l, the adjacent ends of the lever and stop may have cooperating cam surfaces in order to permit a return of the lever to no-load position in the event that the stop 46 has in the meantime been returned to interrupting position.

In the electrical arrangement shown in Fig. 3, the numeral 6i designates a pulley which may be appropriately driven from the axle of the locomotive and which is fixed upon the rotor of a generator 52. A wire 53 connects the generator with a solenoid coil 54 and a second wire 55 connects the generator with an adjustable resistance 56 which is in turn connected by a wire 51 with the solenoid. A magnetic core 5| is slidably mounted within the solenoid and is provided with a stop 59 for engagement with the lower end of a throttle lever 00. The stop is normally actuated outwardly to the interrupting position shown by a coil spring ii.

In the operation of this electrical arrangement, the resistance 56 will be so adjusted that, for any predetermined speed of the locomotive, the current output of the generator 52 will be suflicient to cause the coil 54 to withdraw the stop 59 from interrupting position and upon a drop in the speed of the locomotive below this predetermined speed, the spring Gl will return the stop to the position shown. As in the two modifications discussed above. the adjacent ends of the lever and stop are provided with cam surfaces for the purpose already stated.

Whichever of the modifications is employed, it is apparent that the shifting crew is positively prevented from coupling more cars to the locomotive than the latter can initially move for the throttle opening indicated. Therefore, there is always provided a suilicient reserve of power to insure a desirable acceleration of the coupled train and it is contemplated that, after the mechanism is once adjusted, it will be incapable of unauthorized change by the train crew.

I claim:

1. A throttle control mechanism for an engine driven vehicle comprising in combination, a throttle lever operable between no-load and fullload positions, means for limiting the movement of the lever to a predetermined intermediate position when moved toward full-load position below a predetermined speed of the vehicle, and means for releasing the lever for continued movement toward full-load position when the vehicle exceeds this speed.

2. A throttle control mechanism for an engine driven vehicle comprising in combination, a throttle lever operable'between no-load and fullload positions, a stop for limiting the movement of the lever to a predetermined intermediate position when moved toward full-load position, and means for withdrawing the stop to permit further movement of the lever when the vehicle attains a predetermined speed.

3. A throttle control mechanism for an engine driven vehicle comprising in combination, a throttle lever operable between no-load and fullload positions, a stop, and means for automatically positioning the stop to limit the movement of the lever to a predetermined intermediate position when moved toward full-load position below a predetermined vehicle speed, and for automatically withdrawing the stop to permit further movement of the lever above said speed.

4. A throttle control mechanism for an engine driven vehicle comprising in combination, a throttle lever operable between no-load and fullload positions, a stop for limiting movement of the lever to a predetermined intermediate position when moved toward full-load position, and means connected to and controlled by the speed of the vehicle axle for withdrawing the stop to permit further movement of the lever when the vehicle attains a predetermined speed.

5. A throttle control mechanism for an engine driven vehicle comprising in combination, a throttle level operable between no-load and fullload positions, a stop for limiting movement of the lever to a predetermined intermediate position when moved toward full-load position, means for maintaining the stop in lever-holding position below a predetermined vehicle speed, and means for withdrawing the stop to permit further movement of the lever when the vehicle exceeds said speed.

6. A throttle control mechanism for an engine driven vehicle comprising in combination, a throttle lever operable between no-load and fullload-positions, a stop for limiting movement of the lever to a predetermined intermediate position when moved toward full-load position, a

spring actuating the stop to lever-interrupting position, and means for withdrawing the stop to permit further movement of the lever when the vehicle attains a predetermined speed.

7. A throttle control mechanism for an engine driven vehicle comprising in combination, a throttle lever operable between no-load and fullload positions, a yieldable stop for limiting movement of the lever to a predetermined position when moved toward full-load position, and means for withdrawing the stop to permit further movement of the lever when the vehicle attains a predetermined speed, the lever and stop having cam portions adapted for engagement whereby the stop, if occupying an interrupting position, is depressed when the lever is moved from a position beyond its intermediate position toward no-load position.

8. A throttle control mechanism for an engine driven vehicle comprising in combination, a throttle lever operable between no-load and fullload positions, a stop, a spring tending to hold the stop in a position to limit the movement of the lever to a predetermined intermediate position when moved toward full-load position, a mechanical governor device driven by the vehicle axle, and a connection between the stop and device whereby the' stop is shifted from lever-interrupting position when the vehicle attains a predetermined speed.

9. A throttle control mechanism for an engine driven vehicle comprising in combination, a throttle lever operable between no-load and fullload positions, a cylinder, a piston operable in the cylinder and having a stop projecting externally thereof, a spring in the cylinder tending to hold the stop in a position to limit the movement of the lever to a predetermined intermediate position when moved toward full-load position, a hydraulic pump driven by the vehicle axle, a liquid source. feed lines connecting the source to the pump and cylinder, respectively, a by-pass line connecting the feed lines around the pump, and a valve in the by-pass line adjustable to establish in conjunction with the pump a pressure in the cylinder sufllcient to shift the stop from leverinterrupting position when the vehicle attains a predetermined speed.

10. A throttle control mechanism for an engine driven vehicle comprising in combination, a throttle lever operable between no-load and fullload positions, a solenoid, a magnetic core operable in the solenoid and having a stop projecting externally thereof, a spring tending to hold the stop in a position to limit the movement of the lever to a predetermined intermediate position when moved toward full-load position, a generator driven by the vehicle axle, and electrical connections between the solenoid and generator including a resistance adjustable to cause a retraction of the magnetic core suflicient to free the throttle lever for continued movement toward full-load position when the generator attains a predetermined speed.

CLESSIE L. CUMMINS. 

